Method and apparatus for filling molds



J, W. BRUNDAGE METHOD AND APPARATUS FOR FILLING MOLDS June 23, 1931.

Filed may 27, v1927 www Patented June 23, 1931 f UNITED. sra'ras PATENT @FFEC JAMES W. BRUNDAGE, OF IKRON, OHIO, ASSIGNOR TO TOEN GAMMETER, OF' AKRON, OHIO METHOD AND APPARATUS FOR FILLNG HOLDS Application filed Iiay 27,

VThis invention relates to methods and apparatus forlling molds such as rubber-heel molds, for example, with plastic material such as a rubber compound.

i My chief objects are to provide for maintaining acontinuous supply of stock in readiness for successive molds to be filled; to provide for applying a strong rolling pressure to stock within the mold cavities to compact 'm it thoroughlyl therein; to provide for economy of power and of labor; and to provide more detailed advantages which will be man ifest;

, Of the accompanyingdrawings:

` F ig. 1 is a vertical section of apparatus emb'odying and adapted to carry out my invention in its preferredv form.

Fig. 2 is a section on line 2 2 of Fig. 1. v

' Referring to thefdrawings, the apparatus 2o in the preferred form here shown comprises a. two-rolly calender orrubber mill 10 adapted to form a sheet 11 of rubber stock from a l bank 12 of the stock in the bight of an upper roll 18 and a lower roll lll and to carry i* the sheet upon the periphery of the lower roll. i

Mounted under the rolls is a pair of horizontal supportingy rails or brackets 15, 15, upon which are superposed a pair of wedgeplates 16, 17'adapted to be adjusted, by setscrews such as the set-screws 18, 19 mounted in plates 23, 223%1 secured to the framing, the set-screws bearing against the thicker ends of the 'wedge plates. llfhe wedge plates are adapted to raise or lower aV guide-table 20 restingupon the upper wedge-plate and held against lateral movement by being fitted for sliding vertical'movement between the end standards 22 of the calender and held against longitudinal movement by the plates 23, 23a.

The guide table is formed in its upper facel with va ginde-way Vfor arnold-carrying slide 24E which Vis'connected with the piston rod 25 of a lfluid-pressure ycylinder *26y which is mounted upony the framing, forfmoving the mold-carrying slide 211 back and. forth under ythe calender rolls to pass a successionyof molds, such as the, rubber-heel mold 27, unf der the lower calender roll ltto be filled with rubber stock therefrom. The mold-carrying 1927. Serial No. 194,647.

slide is provided with upstanding projections such as the flange 28 and the bar 29 for holding the mold in proper position thereon. The mold is formed with a plurality of mold cavities 30, 30 separated by lands such as the lands 31, 3l, which preferably have their faces in the same plane.

To cause the sheet 1l of the rubber stock on the lower calender roll to bank up on the mold and to be forced into the cavities there ofa roll-scraper 32 is slidably mounted in horizontal guide-ways suoli as the guide-way 33 formed in the inner faces of respective side flanges rising from the sides of the guide-table, the scraper being slidably held in the guide-ways by rollers 34, 3% journaled between a pair of forks 84, having' their stems slidably mounted in respective brackets mounted upon the calender frame, the forks being urged downward by compression springs 34", interposed between the respective forks and brackets, and held against rotation by splines 34.

The scraper is formed with an upper beveled edge 35 adapted to scrape the stock from the calender roll and with a lower beveled edge 36 adapted to tit against and wipe the stock into the cavities of the mold 27 as the latter passes under the roll, while the scrapers upper beveled edge is in contact with the roll, the scraper beingheld yieldingly but strongly wedged between the mold and the roll.

For holding the scraper position it is connected at its sides with Va pair of brackets such as the bracket 3?' (Fig. 1) rising from the guide-table, by. toggle links 88, 38, pivoted at 38a, 38 to brackets rising from the scraper, and by a pair of links sach as the link 39, the two pairs of toggle lirl-:s being connected at their elbows by a crossbar 40. The pivots 38a preferably are at such height that when the scraper is in operative position, with the toggles nearly straightened,

in such operati-ve the pivots 38a are approximately on a line between the bar 40 and the middle portion of the scraper, so that the force ofthe toggle will not have a strong tendency to depress either end of the scraper with relation to the other.

lUU

- l The construction as, described is such that the-scraper, shoved by the toggle to its limit of movement imposed by its contact with the floors of the guideways 33 and with the calender-troll '14, will be forced to a less advanced position by contact of a bevel 28a formed on the leading margin of the mold, the rising face of the roll permitting the scraper to be lifted against the force of the springs 34D, until-the operative end of the scraper is sufficiently high for the leading end of the mold to pass under it, whereupon the springs 34h, actingl first through the adjacent roller 34 and laterthrough both rollers .34, hold the scraper down flatly against the mold, in a horizontal position, notwithstanding difference in thickness of successive molds, while the mold ypasses through under the scraper, .the toggles holding the scraper wedged between the roll and the mold.

The scraper 32 is preferably hollow and provided with flexible steam pipes 32a, 32" for keeping it hot so that it will operate without roughingy the stock and to assist in keeping the stock warm as it is forced into-the mold.v

Upon the cross bar 40, between the toggles, is mounted a head 42 which is secured on the lower end vof the piston rod 43 of a vertical fluid-pressure cylinder 44 having its upper end pivoted between a pair of brackets such as the bracket'45 projecting from the respective end standards o f the calender.

Pivoted on a bar 41ZL vconnecting stationary brackets such as the bracket 411) is a moldscraper 41 urged downwardly about the bar .41a by hinge-springs suchas the spring 41c interposed betweenthev scraper and therespective brackets 41h, the bracket having formed thereon a stop 41?1 adapted to jbe abutted by the hub of' the scraper, to hold the scraper in position vfor rollers such as the roller 41f journaled upon the scraper near the ends of its scraping edge to be engaged by respective studs such as thestud 28.b formed on the leading'corners of the mold, so that the outer end of the scraperwill be lifted for the passage-of the leadingend ofthe mold thereunder, notwithstanding difference vin the thicknesses of successive molds, the hinge springs 41.and the force of the stock against the inclinedscraper then lseia'fing to hold the scraper downin proper scraping relation-to the upper mold surface.

The two ends of the cylinder 44 ar'e'connected by respectivefluid-supply and venting a pipes 46, 47 with a four-way valve 48 mounted on'the calender frame adjacent thefpath of the mold-carrying slide 27y and having an actuating lever..49 adaptedtobe engaged by a dog "5.1, mounted upon the mold slide in position to pass between the end of the calender roll 14 and the end standard of thefcalender, to retract the scraper 32 from the calender roll 14 when the slidehas forced the mold completely past the calender roll and the scraper 41. i

The charging and venting pipe 52 of the front end of the slide-actuating cylinder 26, provided with a main valve 56, is also provided with a biy-piass 53 having a fine-adjustment throttle valve 54 for throttlin'g the venting of that end of the cylinder, to compel the mold-carrying slide to move forward at slow speed under the forceof fluid supplied to the rear end of the cylinder through a charging and venting pipe 55, so that the mold will have a slower speed than the peripheral speed of the calender roll 14 and will thus cause a bank 57 of the stock to be maintained between the roll and the mold and willcause thefstock to be wiped into the mold cavities by the roll as well as pressed therein by rolling pressure of the roll.

In the operation of the Vapparatus, the mold-carrying slide 24 with a mold 27 vthereon being retracted to the right-hand limit of its movement as viewed in Fig. 1, the valve 48 is turned by hand to bri-ng the scraper 32 to its operative position in which it is'there shown. The main valve 56 ofthe pipe 52 is then closed and, the fineadjustmentthrottlevalve 54 in the by-pass 53 being appropriately set, the rear end of the slide-actuating cylinder 26 is charged through the pipe 55.

lIn consequence of the throttling effect of the valve 54 the slide-carries the mold 27 vforward under the calender roll, and under and in contact with the scrapers 32 and 41 at a slower peripheral speed than that of the-calender roll. ,'Eachscraper is lifted by contact of the-moldv and thencomes into operation upon the upper face of the mold.

As the scraper 32 scraps the stock from the calender roll the bank 57 is formed to a suflicientY size by the time the mold arrives thereat, or the mold maybe stopped with 'its-leading end under the roll while the bank is enlarged. As the mold is moved farther the stock is compressed in the bight' defined by the mold and the roll, so that stock vof the bank is forced into the mold cavities Vin succession as the mold continues to move forward, and each mold cavity is progressively filled from the forward to the rear` side thereof, the roll wiping the stock into the'cavity, by reason of the rolls relatively fast speed, and also strongly pressing the stock in the cavity, by reason of the forward movement ofthe rolls surface andthe mold and the convergence oftheir faces. A final pressingof vthe stock into the cavitiesis eifected by the wiping action of the bevel face36 of the scraper 32, and the lower face of the scraper'prevents escape of stock from the .forward side of the cavity until the cavity passes out of communication with the bank ofstock,V Y i The progressive filling of -each -mold=cavity results in good expulsion o fthefai'r and the combined wiping action roller-pressing action of the roll thoroughly compacts the stock in the cavity with comparatively little friction between the stock and its confining` members and comparatively little internal friction in the stock, and consequently with economy of power consumption.

As the filled cavities pass the beveled edge 36 of the scraper 32 the stock within the cavity is shearedofi from the bank 57 as well as wiped into the cavities and as the mold passes the scraper 41 a final trimming of the upper faces of the cavity-occupying blanks and cleaning of the lands 31 is effected by that scraper. I

As the mold-carrying slide closely approaches the left-hand limit of its movement as viewed in Fig. 1 the dog 51 engages the lever 49 of the valve 48 and causes the scraper 32 to be withdrawn horizontally from the calender roll`14, permitting the stock-bank 57 and the stock-sheet 11 to be carried on the roll back into the bank 12. Vhen the mold reaches its limit of movement it is lifted from the slide and taken away for the vulcanization therein of the blanks it contains.

The cylinder 26 is then reversed, returning the slide to its right hand limit of movement. rIh-e operation as described is then repeated for the filling of the next mold.

My invention thus provides numerous advantages, including those set out in the above statement of objects.

Modifications are possible within the scope of my invention as dened in the appended claims.

l claim:

1. The method of filling the cavity of a mold with plastic material which comprises wiping the plastic vulcanizable material into the cavity and confining it therein, and compacting the confined material by rolling pressure.

2. A method as defined in claim 1V in which the wiping and rolling pressure compacting of the stock are effected concurrently.

v3. The method of filling the cavity of a mold with plastic vulcanizable material which comprises forcing the stock into the cavity, confining and compacting it therein by applying rolling pressure to the stock progressively across the mouth of the cavity, and removing excess stock by a shearing action directed across the mouth of the cavity, while maintaining the rolling pressure.

4. The method of filling the cavity of a mold with plastic vulcanizable material which comprises relatively moving a supply of stock across the mouth of the cavity and causing the stock to flowthereinto by a wiping ofthe outer region of the supply of stock in a direction toward the mold cavity and in a backward direction with respect to the supplys relative movement past the mold.

5. The method of filling the cavity of a mold with flowable material which comprises flowing a mass of vulcanizable gum stock into the cavity by converging movement of the mold and a stock-pressing member with a mass of stock between'them and confining the stock in the cavity without releasing the pressure imposed by said stock pressing member.

6. The method of filling the cavity of a mold with plastic material which comprises forming the material into a continuous sheet byv passing it between rolls and impelling stock of the sheet into the mold cavity while such stock remains integral with the continuous sheet and shearing off the stock while maintaining the impelling pressure.

7. The method of filling the cavity of a mold with plastic material which comprises holding the mold with the mouth oit its cavity adjacent a sheet of stock carried upon the surface of a rotating roll and scraping the stock from the roll into the cavity.

8. Molding' apparatus comprising a cavitied mold and means for supplying plastic vulcanizable material under pressure to the cavity of the mold and for compacting it therein by rolling pressure and means cooperating with said supplying means for wiping ed excess material from the cavitied face of the mold while maintaining the pressure on the material.

9. Molding apparatus comprising a roll, :i cavitied mold, means for so passing the mold relatively past the roll as to compact in the mold cavity a mass or" stock between the tw and means cooperating with the roll and with the mold for confining compact stock in the cavity7 and for shearing excess stock from the mouth of the mold cavity in the passing of the mold.

10. Apparatus as defined in claim 9 in which the shearing means is so constructed and arranged as to constitute a dam between the mold and the roll.

1l. Molding apparatus comprising a cavitied mold, a member for pressing stock into the cavity of the mold, and means for effecting such converging movement of the two as to press into and confine within the cavity a mass of stock between them.

12. Molding apparatus comprising a roll adapted to carry a sheet of plastic stock on its periphery, a cavitied mold, means for passing the mold relatively past the roll, and means for scraping stock from the roll into the mold an d confining it therein.

13. Molding apparatus comprising a roll adapted to carry a sheetof plastic stock on its periphery, means for passing a mold relatively past the roll in position to receive stock therefrom into its cavity, a scraper, and means for holding the scraper in position as a dam between the roll and the mold.

14. Apparatus as defined in claim 13 including yielding means for urging the scraper into scraping position with relation to the roll and means for so overcoming the same llO yielding means as tol force the scraping edge Y of the scraper circumferentially of the roll to permit the leading portion of the mold to pass the'adjacentend of the scraperrand then to release the said yielding means Vto hold the scraper wedged between the mold. Y

15. Moldingapparatus comprising means for movably supporting almold7 means for moving the mold thereon, and meansfor pressing stock into the mold asy they mold moves past the said pressing means, the means for moving the mold comprising a fluid-pressure cylinder, conduits for charging and venting the two ends of the cylinder and a fineadjustmentthrottle-valve for regulating the venting of one end of said cylinder to regulate the speed of the molds movement past the pressing means, one of the conduits being provided with a by-pass and with a valve within the span of the by-pass, and the roll and the throttle valve being mountedintheby-pass.

l my hand this 16. Molding apparatus comprising means for continuously feeding molds pas?J a bank Vof plastic stock, and means includinga roller to Jforce some of the plasticstock into the mold cavities to confine the same therein said roller having a peripheral speed greater than the linear speed of the molds `in their travel.

17. Molding apparatus comprising a rotary roll forfeeding plastic stock, means for moving a mold tangentially past said roll at a linear speed less than the peripheral speed of the roll, and means mutually engaging the roll and the mold causing the stock to become banked therebetween whereby to lill the mold cavities by a combined wiping and pressing'action.

In witness whereof I have hereunto set 25th day of May, 1927. JAMES W. BRUNDAGE. 

